


Dancing like butterfly wings.

by greysora



Category: ATEEZ (Band), 鬼滅の刃 | Demon Slayer: Kimetsu no Yaiba (Anime)
Genre: Denial of Feelings, Enemies to Lovers, M/M, a kny au but u can read it without having watched it, in which seonghwa is tomioka and hongjoong is shinobu, kind of, kny au, no beta we die like men, seonghwa sighs alot
Language: English
Status: Completed
Published: 2020-10-08
Updated: 2020-10-08
Packaged: 2021-02-25 23:15:47
Rating: Not Rated
Warnings: Creator Chose Not To Use Archive Warnings
Chapters: 1
Words: 4,575
Publisher: archiveofourown.org
Story URL: https://archiveofourown.org/works/21553732
Author URL: https://archiveofourown.org/users/greysora/pseuds/greysora
Summary: In a world where demons and humans could not bring themselves to coexist in tranquillity, world peace was a scarcity, an unreachable dream. Humans go about living their own fragile lives, save for the small ratio of stupidly curious individuals. Each only end up dead in some form or another, and so the number continuously decreases over time. Demons, on the other hand, cause havoc and monstrosity, in attempts to quench their everlasting hunger for human flesh.aka the small demon slayer au no one asked for but here she is.
Relationships: Kim Hongjoong/Park Seonghwa
Comments: 6
Kudos: 121





	Dancing like butterfly wings.

**Author's Note:**

> hi!! I haven't written in a while because I've had a bad writer's block but I've managed to get back to this little baby and finally finish her :)  
> It might seem rushed too :/ but i wanted to finish it and keep it short!  
> It's a kny au but you dont need to have watched it to understand.
> 
> (I do appreciate feedback, but if you comment a spoiler please understand i will delete the comment ignore it!)
> 
> This isn't proof read so apologies in advance for any mistakes

DESTROY

  
  


In a world where demons and humans could not bring themselves to coexist in tranquillity, world peace was a scarcity, an unreachable dream. Humans go about living their own fragile lives, save for the small ratio of stupidly curious individuals. Each only end up dead in some form or another, and so the number continuously decreases over time. Demons, on the other hand, cause havoc and monstrosity, in attempts to quench their everlasting hunger for human flesh. A point comes in the past history, thousands of years from today, where cities were completely wiped out, tainted red. A one-sided, cold-blooded war where the rise of demons peaked so high that it naturally forced the number of humans lower, the lowest it had been since the dawn of demons.

Yet their fruitless efforts to fill their bottomless pits for stomachs did nothing but strengthen not only them, but the resolve of the humans too. From the ashes of their previous downfall they rose; the lifeless cities were rebuilt and a demon slayer corporate came to exist. Only the bravest and strongest few had been recruited at first, until the urgent need for more helping hands grew and eventually it became open to all– as long as there was no difficulties in passing the final examination.

It took up a ranking system of ten divisions, the pillars standing tall and proud above them.

They were the eight most talented and powerful of slayers, hand picked by the head of the corporate himself. Each assigned different duties based on their elemental talents and preferences, but they all shared one goal– destroy demons, save humanity.

One may call the eight friends, some say acquaintances. Small sparks of rumours whispered that things between them were not as smooth, and that feelings of rivalry and competition were heavy in the atmosphere around them. And these are all correct– of course depending on the pair of members you are gossiping about. For instance, where the wind and snake pillars, Choi San and Kang Yeosang respectively, tend to stick together and enjoy a friendly relationship, the water and insect pillars, Park Seonghwa and Kim Hongjoong did not.

In fact, the two are far from friends, or at least, if you ask Seonghwa. Hongjoong would call them best buddies, and Seonghwa will adamantly deny this. Any other pillar will simply shrug and say the two were somewhat here and there between friendship and rivalry, _(sprinkled with sexual tension, the sound pillar named Jung Wooyoung will make sure to add)._

Their first meeting was rather a little...bizarre.

It was a stormy night, and the village to the west of their headquarters was living in absolute hell– _literally,_ almost the entire village had been engulfed by flames when the pillars had arrived. A sudden rise in the number of demons there alerted Eden, who immediately dispatched all six of the pillars at the time. Park Seonghwa, Song Mingi, Jeong Yunho, Kang Yeosang, Choi San and their youngest, Choi Jongho. This was certainly not because Eden decided the demons were greater in strength or quite possibly higher ranked demons, _upper moons_ , but more as to quickly eliminate them and diffuse the situation.

The pillars, for the most part, had no problems with working together. Jongho, Mingi and Yunho immediately took off after setting a race and placing bets on who could take down the most demons. Yeosang stayed besides Seonghwa, mostly whining about how unnecessary it was to send all of them and internally, Seonghwa agreed.

San, on the other hand, was yet to arrive. It didn't bother the others because the wind pillar was more than capable alone, so Seonghwa figured he should just get this over with. Not long after splitting with Yeosang, Seonghwa found himself in a secluded area that seemed to be the outskirts of the opposite side of the city from where they entered. Black smoke was thick in the air, the flames licking every part if the ground they could reach. He'd put out as much as he could _(perks of being the water pillar)_ before he switched his attention to searching for any survivors in need of help.

He squatted down a little, a numb ache in his arms from the number of times he'd swung his blade fiercely on countless demon necks.

It was the sudden wail that pulled him out of his little break, blade immediately in his hand and senses on alert. A few feet away on his left stood a sobbing boy, who looked like he'd seen much better days. Matted hair filled with dirt, pale skin wearing bruises and small scratches. His clothes were ragged and torn in parts, and his feet bare. Slowly hiding away his weapon, Seonghwa approached the young child. He radiated a very human-like aura, so Seonghwa deemed it was safe.

But oh, was he wrong.

Crouching down a little until he was eye level with the child, he gingerly took the kid's hand.

"Hey," he spoke softly, "are you lost?"

The kid, still a little teary, nodded. Seonghwa frowned, maybe the boy had been running from demons and strayed too far? Either way, Seonghwa's priority was to take him somewhere safe.

"C'mon, I'll help you find your family." He stood to his full height, and just as he turned to lead the little boy, a yell cut sharply through the air.

_"Stop!"_

The sensation of flesh ripping apart and burning reached his hand faster than the words reached his ears.

In the next moment, the young child has leaped over him, teeth sharply sinking into Seonghwa's arm. He yelled out more in surprise than pain, stumbling back a little. The boy seemed to stick to him, and Seonghwa struggled with reaching his blade.

 _Fuck_ , was his first thought, his second thought barely in process before the two are suddenly enveloped by a swarm of butterflies. _Colourful, pretty._

Seonghwa was too in awe of the sea of beautiful butterflies to register the disappearance of the weight on his arm. 

It was only once the colourful ocean parted did he notice the graceful figure up in the dark sky. He watched as they spun elegantly, their beautiful kimono spreading under their arms to shape them as one of the pretty butterflies. 

Seonghwa could only watch, stuck in a trance, as the figure faced him and charged right at him, blade in hand. It didn't even cross his mind that the unfamiliar person could potentially be aiming to slice _his_ neck. Regardless, they were much too quick for Seonghwa to even have moved if he wanted to. A huge gust of wind caused his dark bangs to sweep back and away from his forehead, and it was only then that Seonghwa's mind registered that the butterfly was now behind him. He spun around, and found his eyes trained on delicate hands that spun around an oddly shaped blade, hiding it from his view a moment later.

The man had strawberry red hair that fell just above his eyes. His eyes…

Pitch black crystals crafted so sharply it pierced through Seonghwa once they were directed at him. The sharp corner of his lips quirked up a little as he took in the state of Seonghwa's arm, and that's when Seonghwa noticed the rotting body of the child demon by his feet. _Nice._

"My my, the water pillar has a soft spot for kids, huh?" The unknown man grinned, showing teeth. He stepped forward and gently grasped the wrist of Seonghwa's injured arm.

However, once icy fingers met warm skin, Seonghwa violently flinched out of the man's reach.

"Who are you?" It came out harsher than he intended, but this man was a complete stranger who may have apparently just saved him, but still a stranger.

"Me? I'm Kim Hongjoong!" His enthusiasm was met with silence and a pout formed on his lips, "you're supposed to say: nice to meet you."

Seonghwa was bewildered by this strange man and his fucking energy. _Who has this much energy in the middle of hell?_

Whatever, Seonghwa had a task at hand and this stranger was not going to interfere.

At least, that's what he thought. Because one moment Seonghwa was sidestepping Kim Hongjoong, and the next, his back was against the burnt ground, a weight on his chest. Hongjoong laughed airily, feet planted firmly on Seonghwa's chest. He was crouched down, face close to Seonghwa's.

What surprised Seonghwa was that his first thought wasn't _what the fuck is the man doing?_ But rather a _jesus was Hongjoong beautiful._

He chose to voice his second thought, causing Hongjoong to giggle.

"Fixing your arm, idiot." He shook his head, "you really are as dull as they say."

"Excuse me?" Seonghwa was _baffled._ This man just–

Who even says–

Hongjoong shushed him as he pulled out a syringe. Seonghwa watches him, his tongue peeking out and eyebrows furrowing as he concentrated on filling it with some kind of medicine.

"Are you afraid of needles?" The question caused Seonghwa's eyebrows to _shoot_ towards his hairline.

_"What kind of pillar is scared of fucking—"_

A surprised scream was viciously torn out of his throat, interrupting his own sentence.

"I just needed a yes or no, buddy." Hongjoong's grin was so twisted but his eyes shine innocently as if he _didn't_ just _stab_ Seonghwa with the needle. The water pillar promises himself to shred the man apart with the strongest form of his attacks after this.

"You can get off me now, you know." For the second time that night, Hongjoong shushed him. This time a finger pressed against his lips.

"You're prettier when you're not talking, you know."

That does it. Seonghwa's fingers reached his own blade, and he prepared to take it out and slice Kim Hongjoong into _pieces—_

"Seonghwa!" He recognised the voice in an instant as San. The rush of wind that engulfed them confirmed it to be the wind pillar approaching them. 

"Oh, I see you've met Hongjoong!" San cheerfully crouched beside them.

"You know him?" If Seonghwa's eyebrows raised any higher, they'd be considered a part of his hairline.

San nodded, "Master Eden has been considering him to join the pillar, so he asked me to work with him and assess him. He's amazing isn't he?"

Seonghwa didn't answer, mind too busy processing the first part. _Join the pillars? This annoying insect was joining the pillars?_

"He was alright." He finally managed to say.

"I saved you." A finger poked his forehead, "that makes me _more_ than alright."

Seonghwa ignored him because then, something else clicks into place. He threw an accusatory glare at San, "so _you're_ the one who told him I'm dull?"

San stuttered, so Hongjoong laughed and turned Seonghwa's face to him again.

"If you don't want to be called dull, you'll have to start working on that tone, baby."

Seconds later brought the three drenched in water, with Hongjoong floating away into the night sky, his laughter ringing in Seonghwa's ears.

Sharp blade in hand, the water pillar turned to the wind pillar.

"I _hate_ him."

  
  
  


And it was from that point on that Seonghwa came to the decision to religiously keep Hongjoong at a distance. Which is laughable, because no one could keep him– _and his stupid smile–_ away. Even through all the insults and teasing grounds they've built throughout the few years, Seonghwa couldn't rid himself of the small sticky feeling that _always_ crept into his stomach whenever Hongjoong and his boisterous laughter was around to bother him.

It's unfair really, how Hongjoong is so easily likeable. As annoyed and unresponsive Seonghwa tries to remain during any interaction with him, the tiny quirk upwards of the corner of his lips is out of his control. His irritated facade isn't convincing anyone, but he still keeps it up. It was a part of their dynamics at this point. And maybe he keeps at it so Hongjoong would continue bothering him and trailing around to tease him, but that's no ones business. 

Seonghwa shakes his head– that's enough thinking about Hongjoong. Now is not the time to be distracted, especially when the man in mind is currently hot on his heels. The moon shines brightly in the dark blanket of the sky, serving as a small lamp to guide them through the tall trees.

After an emergency meeting with master Eden, the founder of the corporation, the two pillars set off to the shady mountain in which havoc was wrecking. Countless lower ranked slayers have been sent, yet none have been able to return from the dark woods and report back and so, Eden decided to dispatch a couple of highest ranked, the pillars. He deemed a moon demon may be residing there. The moons were the most powerful of demons, and they consisted of twelve in total. Six lowers, six highers. The lowers were almost a piece of cake for the pillars to deal with however, Eden did not want to send one of his men alone.

 _"The two of you work best together," he raised a hand at Seonghwa's sound of protest, "look, you may bicker a lot or I don't know if this is some kind of foreplay for you–"_ "Master!" _"–but you know that you are at your best when partnered together. So, you're both going." Eden smiled, satisfied with the acceptance he met, although a disgusted expression tainted Seonghwa's features and Hongjoong wore a maniacal grin and a teasing glint in his eye. He trusted the two to put aside whatever this was and complete their task._

"Are you really going to sulk throughout this mission?" it's followed by Hongjoong's airy laugh.

Seonghwa sighs through his nose, and picks up his speed. It's fruitless, because of course Hongjoong can keep up. If anything, the insect pillar is even faster than Seonghwa, being lighter and fairy-like.

"C'mon Seonghwa, I can't be _that_ bad."

"Oh if only you knew."

Hongjoong laughs again and it gives Seonghwa a hard time, keeping a blank expression.

"Okay, okay. Let's put personal grudges aside and do a good job, hmm?"

Seonghwa remains quiet for a moment, before inclining his head a little, "I'll cover the east side." He says shortly.

Hongjoong clasps his hands together, "perfect, I'll cover the west."

Small fingers wrap gently, a little too gently, around Seonghwa's wrist. He doesn't stop dashing through the woods, though he slows his pace down a little. Hongjoong brings Seonghwa closer to him, close enough that Seonghwa can almost count the small freckles scattered like small star constellations across the high bones of Hongjoong's cheeks. Hongjoong's lips curl a little, "try not to get any scars on your pretty face, hm?" He says in a light tone, though the serious look in his eyes shows he means well. Seonghwa stares at him for a moment, unsure of whether to shrug him off or wish him well too. He opts for a grumble instead, then bolts in the general east direction.

They have their constant insulting and teasing moments, and then there's….these.

Where Hongjoong's eyes would flicker to Seonghwa's, not a single hint of playfulness in them. He'd say something, something genuine and open, honesty swirling so evidently in his eyes. Like he really cares.

Seonghwa, unused to this kind of attention, would freak out, say something a little harsh or look away, desperate to return back to their harsh and insulting normal. It never really lasts for more than a few moments, because Hongjoong would then throw a jab at him or smoothly change topics.

And it always leaves Seonghwa so confused.

Because it doesn't make sense for Hongjoong to _care_ for him, they're supposed to be arch enemies! 

_But Why is that?_ a small voice whispers in the back of Seonghwa's head, _why can't they care for each other?_

He's afraid, he supposes. Of feeling things he shouldn't. _Why not?_ He doesn't know, it just feels wrong.

 _Or maybe,_ a small part of him whispers, _maybe he's afraid of rejection._

That can't be it, he's sure he's just weirded out by the idea of being _soft_ towards Hongjoong when all he's known is being aloof and abrasive. But a part of him he can't deny wants that, the balance between being able to hold Kim Hongjoong in his arms and kiss him senseless, and being able to throw harsh insults without worry of hurting the other.

_Whatever. It's weird, and besides, who's to say Hongjoong would want the same?_

He's almost covered the entire eastern area with little to no events occurring. It's only towards the end of his trek does he meet Hongjoong again. It's not under their usual circumstances though, as Seonghwa shields a young boy and his sister from the insect pillar's sudden attack. 

The boy is covered in blood, and his sister unconscious.

"What's the matter, Seonghwa?" Hongjoong's lifting an eyebrow, face passive and unreadable.

"Don't tell me you haven't noticed–"

"I have." Seonghwa cuts him off. He's aware the two siblings were not normal nor entirely human. He knows this and a time where he himself almost ended their lives flashes in his mind. It took him a moment to remember the pair, having not seen them since that incident two years back.

He was well aware the younger sister was not human when he let them go. The brother he remembers was weak and powerless, but the one he is currently defending almost killed _a lower moon five on his fucking own._ Not to mention his demon sister aided in this, she helped in destroying her own kind. That told Seonghwa enough, the two could not die here.

"Run," he whispers to the boy who was almost losing consciousness, "run and take your sister. Don't you dare stop now, not here."

The boy hesitates, before he finally whispers a genuine, heartfelt thanks and gathers his sister in his arms, disappearing into the darkness of the woods.

Releasing a sigh, Seonghwa turns to lock eyes with the man before him, face as passive as ever.

"Seonghwa," Hongjoong starts slowly, "why are you protecting a _demon?"_

Seonghwa's grip on his blade tightens, the last thing he wants to be doing right now is fighting Hongjoong, but he needs to buy the two kids enough time, "that's none of your concern."

"I am a _pillar,_ this is my fucking business." Hongjoong snaps back at him. Confusion swirls with anger in his eyes, dark crystals harder than ever.

"This demon is different, Hongjoong."

Hongjoong barks a short laugh, "is that so? And how is it different?"

Seonghwa watches as Hongjoong aims the tip of his blade at him, "forget that, if you want me to get through you first that won't be a problem. Since my blade is specialised in poisoning, I will just temporarily paralyse you."

He lunges at Seonghwa who retaliates. He remains on the defensive, and after a few hits and blocks, Hongjoong grits his teeth in annoyance, "what's the matter, you're not gonna fight me?"

Silence stretches in the small space between them as the blades clash. Seonghwa watches as puzzlement twists Hongjoong's features before realisation dawns on him.

"Oh, what's this? You're stalling me for time?" He laughs a genuine laugh of surprise, "you think they can outrun me?"

"No," Seonghwa's eyes lift to lock Hongjoong's in place.

"Whatever, I don't have time for this." With that, the insect pillar leaps into the air and disappears into the woods.

Seonghwa sighs for what seems like the nth time that night, before following suit.

You'd think this is where Hongjoong catches up to the kids and quickly ends the demon of the two. Considering he is among the fastest pillars, this should have been the case. But alas, twenty minutes later finds Hongjoong whining and kicking his feet about, head trapped in a lock of arm.

"Park Seonghwa, _let me go!"_ He claws blunt nails into the arm around his neck, "this is why no one likes you, you're playing dirty!"

He does agree it's a dirty trick, using their body size differences to his advantage but well, what choices did Seonghwa have?

It's an awkward headlock, where he is holding the smaller backwards. He figures it would have been better than close proximity. That in itself would be a distraction. 

What he _didn't_ anticipate, however, was the foot coming up and aiming for his face. And, the cherry on top? The fucking _dagger_ that stuck out at the back of the shoe.

So naturally, to save face, _literally,_ Seonghwa yells the first thing that comes to his mind.

_"Kim Hongjoong, date me."_

The shoe freezes in time, and so does the body beneath him. Heck, so does Seonghwa himself, unsure of what just happened. All he knows is his face isn't in pain nor bleeding. 

Slowly, the shoe comes back to the ground. The insect pillar ceases struggling and so Seonghwa loosens his grip. Until he's let go and Hongjoong is facing him directly.

His face is void of any previous traces of humor, and suddenly Hongjoong _looks_ his small size. It makes Seonghwa wonder exactly why he hasn't laughed it off like expected off him. The silent man before him frightens him, and the fear of rejection truly shakes him.

Yeah, he said those words for distraction, but it wasn't a lie. Instead, it was as if Seonghwa allowed the smallest voice in his heart to step up the platform and speak into the microphone for once. It was true and _he meant it._

"It's not nice of you to play with other people's feelings, Seonghwa." The words punch him harder than any blow could have ever, and he stands rooted and useless as Hongjoong brushes past him without further speech. Soon, the water pillar is stood alone under the dark blanket of the sky.

Seonghwa doesn't understand. Why would Hongjoong seem so upset over such a thing, why did he not just throw an insult like he usually would? His eyebrows furrow in confusion, could it be, that Hongjoong too has feelings for Seonghwa? _No, that just seems much too far-fetched._

"You're thinking too loudly man, the answer is right in front of you." If Seonghwa jumped out of his fucking skin at the sudden voice, it's nobody's business.

He exhales a sharp breath before turning to face the figure who lazily drapes himself high up over a thick branch in one of the surrounding trees, Jung Wooyoung. Because of course it's fucking Wooyoung, the sound pillar. Also known as the only pillar that can silently sneak up on the others thanks to his element.

"What are you talking about?" Feigning innocence should work quicker to bore one like Wooyoung. At least Seonghwa thinks so.

 _Hold on,_ he thinks, _why is Wooyoung even here?_

"Oh c'mon buddy, do I need to spell it out for you?" At Seonghwa's blank expression, the sound pillar groans in impatience and snaps a twig from the bark of the tree. Carefully, he throws his body down to where Seonghwa stands and lands on his feet, _without a sound,_ before searching the ground. Seonghwa watches him in puzzlement as he lets out a sound of victory (at finding some soft muddy patch?) some steps away from where he landed.

It then hits Seonghwa that he _really_ meant writing it out–

_"Wooyoung–"_

"Seonghwa...likes...Hongjoong…" Wooyoung begins to speak his sentences out loud and Seonghwa almost rips him into pieces.

"Tada!" Wooyoung steps back to admire his small paragraph. However, his victory is short lived and he pouts angrily once Seonghwa has washed away the words.

"Fine!" Woyoungs huffs before stomping away, "I'm not the one who's continuously pining over his _crush_ because he couldn't grow a pair of–" Seonghwa tunes him out, and wills himself not to sigh.

Kim Hongjoong is a healer, so finding him is not much of a difficult task, the smell of medicinal herbs lead Seonghwa to a small clearing towards the western side of the mountain. Hongjoong is kneeling before a young boy, with bright blondish orange strands of hair. He remains quiet as he watches Hongjoong pat the other's hair, telling him he did a good job and that his body will recover soon. Warmth spreads in Seonghwa's chest as the boy visibly relaxes at Hongjoong's soothing voice and calming words.

Once the insect pillar rises to his feet though, he spins around slowly and finds Seonghwa, eyes filled with a look of fondness that shakes his core. A quick glance around tells Hongjoong he still has a handful of patients left and he turns his back to Seonghwa once again before making his way to another slayer who cries with pain.

To Hongjoong's utter surprise, Seonghwa also crouches down beside him and smiles softly at the patient, before taking her hand and reassuring her that everything will be okay. That her body will recover.

That she is in the care of the galaxy's best healer.

An emotion that Hongjoong can't seem to name clutches and squeezes at his heart painfully, before he throws a grin at their patient and gets back to work.

They do this for the remaining group of injured ones, without exchanging a word once. But it's a good silence, a calming silence.

Once Hongjoong finishes arranging his medicine syringes and bottles carefully, and there are no more patients to attend to, he faces Seonghwa once again.

"Thank you," he smiles and it is genuine.

Seonghwa swallows, "Hongjoong I–"

"Would you like to watch the sunrise with me?"

It's enough to send Seonghwa's mind spinning and he nods immediately, maybe a little too desperately but it's only natural after denying himself this for the years he's known Hongjoong.

He follows Hongjoong's light leaps across the treetops until they reach the clearing right at the peak of the mountain.

Seonghwa faces Hongjoong's back, before taking a small breath and moving to step in place beside him. He wills himself to say something, to speak–

To tell him what he feels and–

And nature has a funny way of doing things, because the lights of a new day slicing through the dark blanket of the sky abruptly brings an end to his thoughts.

Hues of purple bleed through the tree lines as the day finally breaks through. Hongjoong turns his head and watches the first light of the sun peeking through the horizon. His eyes trail after a flock of birds which emerge from the highest trees in the distance, singing sweetly in tune.

Seonghwa simply stares at him, taking in the sharp lines of his face painted beautifully by the sunlight. He's so caught up in staring at Hongjoong– his eyes, his cheeks, his _lips,_ that he doesn't notice Hongjoong is also drinking him in.

The surge of confidence that suddenly runs through Seonghwa's veins is the only explanation he can give for why he speaks again.

"I meant it, earlier." It comes out soft, the raw honesty in his voice is more intense than he intended. But he can't find it in him to care when the black crystals widen with surprise before searching his eyes. Silence stretches between them and then the crystals melt and soften around the edges.

"No takesies backsies?"

"No takesies backsies."

The corners of Hongjoong's eyes crinkle and he grins, perfect set of teeth on display. 

"Oh, baby. You're gonna regret this."


End file.
